Help...Arrays - Xtreme Visual Basic Talk

03-07-2004, 01:13 AM

solon

Newcomer

Join Date: Mar 2004

Posts: 2

Help...Arrays

Here is some code that I have written, that I wish to use as a random name generator. I would like the program to pick a name at random, then remove it from the array so that it cant be chosen again until all the others have been drawn.

Private Sub Form_KeyDown(keycode As Integer, shift As Integer)
random
End Sub
Private Sub random()
Dim max As Integer
Dim term As Integer
Dim temp As Integer
Dim x(12) As Variant
x(0) = "Huy"
x(1) = "Fershad"
x(2) = "James"
x(3) = "Matthew"
x(4) = "Rudolf"
x(5) = "Tim"
x(6) = "Steve"
x(7) = "David"
x(8) = "Martin"
x(9) = "John"
x(10) = "John"
x(11) = "Daniel"
x(12) = "Nathan"

'max = (x.Count - 1)
' Could use that one!
max = (x - 1)
While (max >= 0)
term = (Rnd * max)
temp = x(max) = x(term)
x(term) = temp
max -1
Wend
End Sub

I can't work out why it won't work, but seeing as though I am a Java programmer, I really don't have much hope!

Please help me "clean up" my code!

Thanks, Solon

03-07-2004, 01:21 AM

BryanN

Banned

Join Date: Feb 2004

Posts: 278

In Form_Load, put the statement
Randomize
this iwll mkae a random number. for the names, you may want to simply use a listbox.

03-07-2004, 01:37 AM

solon

Newcomer

Join Date: Mar 2004

Posts: 2

I understand that, but thanksyou.

The problem lies in the line

max = (x - 1)

Well the program wont compile and i think there MAY be problems after that but it hanst picked them up yet, it is stuck on that one!

It says:

"Type Mismatch"

Thanks...

03-07-2004, 03:18 AM

thingimijig

Senior Contributor

* Expert *

Join Date: Jul 2003

Posts: 1,300

have a look at billsoos tutorial on random numbers here

thingimijig.

03-07-2004, 05:03 AM

Mathijsken Mathijsken is offline

Contributor

Join Date: May 2003

Location: Oostkamp - Belgium

Posts: 730

I can see that you're not used to VB at all, fyi VB doens't support short-notations like max =- 1 or other java-stuff VB is a bit lame in comparison with Java

I've re-written your code a bit:

Code:

Option Explicit
'This is a 'home-made'-type, like a string or variant. The reason i use this,
' is that i don't have to declare to arrays: Chosen() and Names(), but an array
' of this private type
Private Type Names
	 Name As String
	 Chosen As Boolean
End Type
Const NrOfNames As Integer = 12
Dim X(NrOfNames) As Names
Dim strRandom(NrOfNames) As String 'This will contain all the names in a random order.
Private Sub random()
Dim intTemp As Integer, i As Integer
	X(0).Name = "Huy"
	X(1).Name = "Fershad"
	X(2).Name = "James"
	X(3).Name = "Matthew"
	X(4).Name = "Rudolf"
	X(5).Name = "Tim"
	X(6).Name = "Steve"
	X(7).Name = "David"
	X(8).Name = "Martin"
	X(9).Name = "John"
	X(10).Name = "John"
	X(11).Name = "Daniel"
	X(12).Name = "Nathan"
	
	For i = 0 To NrOfNames
		Do While strRandom(i) = ""
	
			Randomize
			intTemp = Int(Rnd * NrOfNames)
	
			If X(intTemp).Chosen = False Then
				strRandom(i) = X(intTemp).Name
				X(intTemp).Chosen = True
			End If
			DoEvents
	   Loop
	Next i
End Sub

The idea is:
1) You loop through a new array of names (strRandom). We'll put our names, randomly selected in this one.
2) You get a random index of the original X array and check wether this one has been chosen before or not. If he has been chosen before pick another random number and another,... untill we get one that hasn't been chosen yet. Then we simply pass the found name to the new array (strRandom).

I don't know what has to happen with the names, tell me and I'l explain you how to acces the random array,or find out yourself, that's up to you I guess

Mathijsken

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03-07-2004, 05:35 AM

tinyjack

Captain TJ

Forum Leader
* Expert *

Join Date: Jun 2003

Location: England

Posts: 1,664

Your initial problem was that arrays in VB do not have a Count property, you need to use the UBound function, so:

Code:

max = (x.Count - 1)
 
'becomes
max = UBound(x)

HTH

TJ

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